CN1309880C - Metal strip for epitaxial coating and method for production thereof - Google Patents

Abstract

The invention relates to a metal strip consisting of composite layers for epitaxial coating and a method for its production. The object of the invention is to provide a metal strip with a particularly high strength and a corresponding production method. The metal strip according to the invention is a composite layer consisting of at least one biaxially textured base layer of the metal Ni, Cu, Ag or alloys thereof and at least one other metal layer, wherein each other metal layer consists of one or more An intermetallic phase consists either of a metal or alloy that contains one or more intermetallic phases. The manufacturing method is characterized in that, at the end of the manufacturing process, an intermetallic phase is formed by interdiffusion of the elements present in the layer. Metal tapes of this type can be advantageously used, for example, as carrier tapes for depositing biaxially textured layers of YBa ₂ Cu ₃ O _x -high-temperature superconductor material. Such high-temperature superconductors are particularly suitable for use in the field of energy technology.

Description

Metal strip for epitaxial coating and method for its manufacture

technical field

The invention relates to a metal strip consisting of composite layers for epitaxial coating and a method for its production. Metal tapes of this type can be advantageously used, for example, as carrier tapes for depositing biaxially textured layers of YBa ₂ Cu ₃ O _x -high-temperature superconductor material. Such superconductors are particularly suitable for use in the field of energy technology.

Background technique

Already known are Ni, Cu and Ag based metal strips suitable for epitaxial coatings with biaxially textured layers (US 5 739 086; US 5 741 377; US 5 964 966; US 5 968 877). They are manufactured by cold rolling with a deformation rate higher than 95% followed by recrystallization annealing, in which a reinforced {001}<100> texture (cubic texture) is formed.

Especially the world is stepping up the development of Ni and Ag-based host materials (J.E.Mathis et al, Jap.J.Appl.Phys.37.1998; T.A.Gladstone et al, Inst.Phys.Conf.Ser.No 167, 1999). It is well known that in an effort to increase the strength of the material, Ni alloys containing typically more than 5% of one or more alloying elements are rolled and recrystallized, either by solid solution quenching (US 5 964 966; G. Celentano et al , Int.Journal of Modern PhysicsB, 13, 1999, S.1029; R.Nekkanti et al., Presentation at the Applied Supercond.Conf., Virginia Bcach, Virginia, Sept.17-22, 2000), or by combining Ni with Composite materials made of a higher tensile strength material were rolled and recrystallized (T. Watanabe et al., Presentation at thc Applied Supercond. Conf., Virginia Beach, Virginia, Scpt. 17-22, 2000).

During solution hardening there is a critical additive content above which the formation of a cubic texture is no longer possible. This phenomenon has been intensively studied for copper-zinc alloys (Cu-Zn alloys with increased Zn content) and seems to be generally valid (H.Hu et al., Trans.AIME, 227, 1963, S.627; G.Wasserman, J. Grewen: Texturen metallischer Werkstoffe, Springer-Verlag Berlin/Gttingen/Heidelberg). Since the strength always increases with the alloy concentration, there is also a maximum strength involved. The second limitation is that the strength of the material is already high at the time of rolling deformation. Therefore, when it is required to increase the deformation rate, a very large rolling force is required. Therefore, on the one hand, it is necessary to put forward higher requirements on the rolling mill. On the other hand, it is technically difficult to implement extremely uniform rolling deformation, which affects necessary to form the desired highly cubic texture.

When increasing the strength by rolling composite materials, there is also the problem that high-strength materials require high rolling forces when they are highly deformed. Due to the different mechanical properties of the two materials that make up the composite, heterogeneity in the deformed microstructure occurs during rolling, which reduces the quality of the cubic texture that can be achieved during recrystallization.

Intermetallic phases have significantly higher strength than solid solution alloys. However, they are generally very brittle and so cannot be used to make thin ribbons with a pronounced cubic texture.

Known especially the so-called intermetallic γ`- and γ``-phases (Ni ₃ Al, Ni ₃ Ti, Ni ₃ Nb), the strength does not decrease with increasing temperature like solid solutions, but even increases . Thus, it is precisely at critically high temperatures (>600° C.) that metal strips strengthened by these phases develop much higher strengths than conventional metal strips during coating.

Contents of the invention

The object of the present invention is to provide an epitaxially coated metal strip which has a particularly high strength. The invention also includes a method for producing such a high-strength metal strip without technical problems.

This object is thus achieved with a metal strip consisting of a composite layer consisting of at least one biaxially textured base layer of the metal Ni, Cu, Ag or alloys thereof and at least one other metal layer, wherein each other metal A layer consists of one or more intermetallic phases or of a metal or alloy which contains one or more intermetallic phases.

According to the first object-based configuration of the present invention, in the case of a biaxially textured base layer consisting of Ni or an Ni alloy, each other metal layer is composed of a base metal with at least one metal Al, Ta, Nb, Ti or an alloy thereof. Composition of intermetallic phases.

According to a second embodiment of the invention according to the object, in the case of a biaxially textured base layer consisting of Ni or a Ni alloy, each other metal layer consists of at least one metal Al, Ta, Nb, Ti or an alloy thereof, which contains Intermetallic phases of metals Al, Ta, Nb, Ti or their alloys with base metals.

The intermetallic phase may consist of NiAl, Ni ₃ Al, Al ₃ Ni ₂ , Al ₃ Ni, NiTa, NiTa ₂ , Ni ₃ Ta, Ni ₃ Nb, and/or Ni ₆ Nb ₇ depending on the purpose.

According to a further embodiment of the invention, if the biaxially textured base layer consists of Cu or a Cu alloy, the respective further metal layer consists of an intermetallic phase of Cu or a Cu alloy with Zn.

In the case where the biaxially textured base layer consists of Cu or a Cu alloy, each other metal layer also consists of Zn, containing an intermetallic phase of Cu or Cu alloy and Zn.

In this respect, the intermetallic phase of Cu or Cu alloy with Zn is β- and/or γ-brass.

According to a further embodiment of the invention, in the case of a biaxially textured base layer consisting of Ag or an Ag alloy, the respective further metal layer consists of an intermetallic phase of Ag or an Ag alloy with Nd.

In the case where the biaxially textured base layer consists of Ag or an Ag alloy, each other metallic layer also consists of Nd, containing an intermetallic phase of Ag or Ag alloy and Nd.

In this aspect, the intermetallic phase of Ag or Ag alloy with Nd consists of Ag ₅₂ Nd ₁₄ , Ag ₂ Nd, and/or AgNd.

According to an advantageous embodiment of the invention, the composite layer consists of two biaxially textured base layers and a further metal layer, wherein the further metal layer is arranged between the biaxially textured layers.

For the production of such a metal strip, the invention comprises a method in which first a composite layer is produced consisting of at least one layer of the metals Ni, Cu, Ag or alloys thereof suitable for biaxial texture and at least one other metal layer . In this respect, an element which can form an intermetallic phase with the layer suitable for the biaxial texture must be contained in the other metal layer.

Thereafter, the composite layer is rolled into strip with a deformation rate of at least 90%. Finally, by means of a heat treatment between 300°C and 1100°C, in layers suitable for biaxial texture and in other layers, the required cubic texture is formed by interdiffusion at the interface of the intermetallic phase composite layer.

The composite layer is produced in a suitable manner by electroplating and rolled into strip with a deformation rate of at least 95%. The heat treatment of the strip is especially suitable for temperatures between 500°C and 900°C.

A variant of the method according to the invention consists in firstly producing a biaxially textured strip of Ni, Cu, Ag or alloys thereof by rolling and recrystallization. Such a tape is then coated with at least one other metallic phase comprising at least one metal containing an element capable of forming an intermetallic phase in the biaxially textured tape. The coating method can be, for example, electrolytic, chemical or also deposition from the vapor phase. During the subsequent heat treatment, a stable intermetallic phase is formed starting from the boundary layer.

As an option for the coating, as long as the melting point of the biaxially textured tape is significantly higher than that of other metal phases, one side of the biaxially textured tape can also be wetted with liquid other metal phases, and then diffused into the biaxially textured tape , thus forming an intermetallic phase starting from the surface of the biaxially textured belt.

High-strength biaxially textured metal strips can be produced in a relatively simple manner using the method according to the invention. A particular advantage here is that the metal strip still has advantageously low strength and high ductility during the deformation process, since the high-strength intermetallic phases are only formed in the metal strip during the final annealing treatment. The cubic texture is not affected by the different kinetics of the recrystallization and diffusion processes.

The metal tapes according to the invention are particularly suitable as carrier tapes for depositing biaxially textured layers of YBa ₂ Cu ₃ O _x -high-temperature superconductor material. This type of superconductor is particularly suitable for energy

used in technical fields.

Detailed ways

The present invention is described in detail below with the aid of examples.

Example 1

A three-layer composite layer consisting of metallic Ni and Al is produced by roll plating with the sequence Ni/Al/Ni. The Ni layer has a thickness of 1.5 mm, and the Al layer has a thickness of 0.5 mm. This composite layer was rolled into a strip having a thickness of 80 μm. The tape was then placed in a reducing atmosphere at a temperature of 600° C. for several hours. The ribbon recrystallizes during the first few minutes of this heat treatment. In the continuation of this heat treatment, NiAl phases of different stoichiometry are created and increased on the boundary layer.

The finished tape has a high degree of cubic texture on its surface, which is particularly suitable for double-sided epitaxial coating with biaxially textured layers.

The yield point of this belt at room temperature is 100 MPa, and it does not change up to a temperature of 600°C. Thus, the material has a greatly increased strength at the temperature of the coated metal compared to conventional, especially solid solution hardened metal strips.

Example 2

A three-layer composite layer consisting of metallic Ni and Nb is produced by roll plating with the sequence Ni/Nb/Ni. The Ni layer has a thickness of 1.5 mm, and the Nb layer has a thickness of 0.5 mm. This composite layer was rolled into a strip having a thickness of 40 μm. The tape was then placed in a reducing atmosphere at 900° C. for 1 hour. The ribbon recrystallizes during the first few seconds of this heat treatment. During the continuation of annealing, NiNb phases of different stoichiometry are generated and increased on the boundary layer.

The finished tape has a high degree of cubic texture on its surface, which is also suitable for double-sided epitaxial coating with a biaxially textured layer.

The yield point of this belt at room temperature is 85 MPa, and it does not change up to a temperature of 600°C. Thus, the material has a greatly increased strength at the temperature of the coated metal compared to conventional, especially solid solution hardened metal strips.

Example 3

Pure Ni biaxially textured ribbons 40 μm thick were produced by rolling and recrystallization, heated to 800 °C and coated with a 10 μm thick Al film on the uncoated side. Due to the action of the heat treatment, the Al film melts, and the Al diffuses into the Ni, thereby forming NiAl phases of different stoichiometry from the surface of the Ni ribbon through interdiffusion.

The yield point of this belt at room temperature is 90 MPa, and the temperature does not change up to 600°C. Thus, the material has a greatly increased strength at the temperature of the coated metal compared to conventional, especially solid solution hardened metal strips.

Example 4

A three-layer composite layer composed of metallic Cu and Zn is produced by roll plating with the sequence Cu/Zn/Cu. The thickness of the Cu layer was 1.5 mm, and the thickness of the Zn layer was 0.7 mm. This composite layer was rolled into a strip having a thickness of 50 μm. The tape was then heated to 800° C. at 30 K/min and held for 60 minutes. During this annealing, an enhanced stereotexture is first formed, followed by a brass phase with different stoichiometry starting from the Cu-Zn interface.

The finished tape has a high degree of cubic texture on its surface, suitable for double-sided epitaxial coating with a biaxially textured layer. The yield point of the belt at room temperature is 80Mpa, and it drops to 30Mpa at 750°C as the temperature rises. Therefore, the strip strength is significantly higher than that of other Cu alloy strips with stronger rolled biaxial texture.

Claims (19)

1. the metal strip that is used for the extension coating, form by composite bed, it is characterized in that, composite bed is by metal Ni, Cu, Ag's or its alloy at least one biaxial texture basic unit and at least one other metal level are formed, and wherein, each other metal levels are formed by one or more intermetallic phases or by a kind of metal or alloy that wherein contains one or more intermetallic phases.

2. by the described metal strip of claim 1, wherein, under the situation of basic unit by Ni or Ni alloy composition of biaxial texture, each other metal levels are by parent metal and at least a metal A l, Ta, Nb, the intermetallic phase composition of Ti or its alloy.

3. by the described metal strip of claim 1, wherein, under the situation of basic unit by Ni or Ni alloy composition of biaxial texture, each other metal levels are by at least a metal A l, Ta, Nb, Ti or its alloy composition wherein contain described metal A l, Ta, Nb, the intermetallic phase of Ti or its alloy and parent metal.

4. by claim 2 or 3 described metal strips, wherein, intermetallic phase is by NiAl, Ni ₃Al, Al ₃Ni ₂, Al ₃Ni, NiTa, NiTa ₂, Ni ₃Ta, Ni ₃Nb, and/or Ni ₆Nb ₇Form.

5. by the described metal strip of claim 1, wherein, under the situation of basic unit by Cu or Cu alloy composition of biaxial texture, each other metal levels are made up of the intermetallic phase of described Cu or Cu alloy and Zn.

6. by the described metal strip of claim 1, wherein, under the situation of basic unit by Cu or Cu alloy composition of biaxial texture, each other metal levels are made up of Zn, wherein contain the intermetallic phase of Cu or Cu alloy and Zn.

7. by claim 5 or 6 described metal strips, wherein, the intermetallic phase of Cu or Cu alloy and Zn by β-and/or γ-brass form.

8. by the described metal strip of claim 1, wherein, under the situation of basic unit by Ag or Ag alloy composition of biaxial texture, each other metal levels are made up of the intermetallic phase of described Ag or Ag alloy and Nd.

9. by the described metal strip of claim 1, wherein, under the situation of basic unit by Ag or Ag alloy composition of biaxial texture, each other metal levels are made up of Nd, wherein contain the intermetallic phase of described Ag or Ag alloy and Nd.

10. by claim 8 or 9 described metal strips, wherein, the intermetallic phase of Ag or Ag alloy and Nd is by Ag ₅₂Nd ₁₄, Ag ₂Nd, and/or AgNd forms.

11. by the described metal strip of claim 1, wherein, composite bed is made up of basic unit and other metal levels of two biaxial textures, wherein, other metal levels are arranged between the biaxial texture layer.

12. be used to make method by one of claim 1-11 described metal strip, it is characterized in that, at first make composite bed, by metal Ni, Cu, at least one of Ag or its alloy is suitable for layer and at least one other metal level of biaxial texture and forms, wherein, contain at least a element that can constitute intermetallic phase at other metal levels, after this, this composite bed is rolled into band with at least 90% deformation rate with the layer that is suitable for biaxial texture, at last, by means of the band thermal treatment between 300 ℃ and 1100 ℃, in the layer that is suitable for biaxial texture and other layers, constitute desired cubic texture by the phase mutual diffusion on the intermetallic phase composite bed interface.

13. by the described method of claim 12, wherein, composite bed is made by electroplating.

14. by the described method of claim 12, wherein, with the rolling composite bed of at least 95% deformation rate.

15. be used to make method by one of claim 1-11 described metal strip, it is characterized in that, at first by rolling and recrystallize manufacturing by Ni, Cu, the biaxial texture band of Ag or its alloy composition utilizes this band at least a other metallographic phase coatings subsequently, and this metallographic phase comprises at least a metal that can form the element of intermetallic phase in the biaxial texture band that contains, during the thermal treatment of back, constitute stable intermetallic phase from the frictional belt.

16. by the method for the described manufacturing metal strip of claim 15, wherein, for coating metal use electrolytic, chemistry or from vapour phase sedimentary method.

17., wherein, under the temperature between 500 ℃ and 900 ℃, heat-treat by claim 12 or 15 described methods.

18. by the method for the described manufacturing metal strip of claim 15, wherein, as long as the fusing point of biaxial texture band apparently higher than other metallographic phase, soaks biaxial texture band single face with other liquid metallographic phase,

19. press the described metal strip of claim 1-11 as depositing by YBa ₂Cu ₃O _xThe carrier band of the biaxial texture layer that-high-temperature superconductor material is formed uses, and is used to make banded high-temperature superconductor.